It is important to include in your tree ordinance definitions of technical terminology and other terms that have specific or unique meanings as used in the ordinance.  Putting all of these definitions in their own section, as opposed to defining them as they occur in the ordinance, will increase the conciseness and clarity of your ordinance.

It is a good idea for your definitions of technical arboricultural terminology to be consistent with standard arboricultural and forestry terminology and definitions.  Ideally, basic arboricultural definitions such as those for caliper, critical root zone, DBH, dripline, and tree should be standardized from one community to another.  Using one of the sources of standard arboricultural definitions listed below will promote this consistency.

Non-arboricultural definitions that you wish to include should be consistent with those cited in other parts of the city or county code, such as zoning or stormwater ordinances.  This will reduce confusion among staff and individuals who are implementing the ordinance, and who work with ordinances from various communities.


There are four (4) primary sources of definitions that you can use in developing your ordinance.

  1. Georgia Forestry Commission’s Glossary of Selected Terminologies & Definitions for Community Tree Ordinances
  2. International Society of Arboriculture Online Dictionary (available in multiple languages)
  3. Tree Ordinances from Other Communities, accessible through the Municipal Code Corporation’s online library
  4. Zoning, stormwater, or unified development ordinances in your community for non-arboricultural definitions